The present invention relates to a haymaking machine for the windrowing of crops, for the turning of windrows or for tedding. It includes at least one driven drum rotatable about a substantially vertical or inclined axis and which has, at its base, a flexible and deformable skirt for gripping and carrying the crop.
The skirt includes a continuous thin collar. It has approximately the shape of a truncated cone and extends all around the drum. The skirt passes operatively below the crop to move it, follows closely any unevenness of the ground, sweeps up the crop and carries it on its upper surface.
The skirt replaces advantageously the metal teeth which are used at present in machines of this type. In fact, the crop, which is no longer in contact with the ground as it is being moved, is protected from being contaminated by the earth. In addition, the skirt avoids the risk of any broken forks in presses or forage harvesters used to collect the crop.
In accordance with the cylindrical present invention, the wall of the drum is fitted with arms or arms of elongated shape which help in moving the crop. These bars extend, advantageously, in planes which are substantially perpendicular to the axis of rotation of the drum and are pointed in the direction opposite to the direction of rotation of the drum. The arms are easy to implement and do not give rise to any harmful ventilation.
During operation, the arms prevent the crop from building up against the cylindrical wall of the drum, thereby making possible a very even movement of the crop. In addition, as a result of the direction in which the arms point, they do not get entangled with the crop. Thus, during the windrowing operation, the crop is deposited in even, compact windrows which can be collected easily with a press or a forage harvester.
In accordance with another characteristic of the invention, the arms which are arranged at the lower part of each drum, can be pointed downwardly. In this way, the arms are closer to the skirt and co-operate closely therewith for the purpose of carrying the crop.
In the case of lateral raking operations using a machine which has several drums fitted with arms in accordance with the present invention, the arms serve to partly close the gap between two adjacent drums. In this way, the arms prevent parts of the crop from being lost between the drums.
The arms also prevent the crop from slipping over the skirts on the sides of the machine. As a result of this feature, the width of the crop which is actually raked corresponds to about the external diameter of the skirt. In addition, the arms thus ensure a clear separation between the crop which has been collected during a run and that which is still left on the ground.
In accordance with another important characteristic of the invention, the external end of each arm is bent backwards, as viewed in the direction of rotation of the drum. As a result of this feature, the crop can be released easily from the arms, and is not dragged out of the swath behind the machine. With the same purpose in mind, the arms subtend a convex curve, which, in a plane perpendicular to the axis of rotation, and with increasing distance from the drum outer surface, has a decreasing angle between the convex curve exterior, and a radius part that projects from the axis of rotation of the drum beyond the curve exterior.
In accordance with another characteristic of the invention, the diameter of the trajectories of the arms located at the top part of each drum is greater than that of the arms located at the bottom part of the drum. This is realized, for example, by arranging for such longer arms to be mounted to the top portion of the drum. Consequently, during swathing, a slight compressing effect at the top of the swath is obtained. In addition, when the crop is very dense, the longer arms hold it at their own level and prevent it from passing over the drum or drums. Finally, as a result of their greater circumferential speed, the arms facilitate the turning of swaths which have already been formed.
The outer contour of the skirt of each drum is, however, equal to, or greater than the largest diameter of the trajectories of the arms. Consequently, it is only the skirt which comes into contact with the ground, and this feature alone provides for the gripping of the crop.